In this work, the thermal performance of three different wall configurations was examined by hot box measurements and numerical simulations. Vacuum insulation panels were sandwiched between traditional insulation in walls where the load-bearing elements were standard 36-mm-thick wooden studs, I-profiled studs and U-profiled studs. The measured mean values of the thermal transmittance (U-value) were 0.09 W/m2·K with 36-mm-thick wooden studs, 0.10 W/m2·K with U-profiled studs and 0.11 W/m2·K with I-profiled studs. The comparison of the three wall structures has shown that with such low U-values, the numerical simulations are more sensitive to the accuracy of the dimensions and thermal conductivities used as input. This required measurements of the thermal resistance of the fibreboard in two directions, the thickness and thermal resistance of the vacuum insulation panels and the thermal resistance of the 36-mm-thick wooden studs and the mineral wool.
Zero emission buildings (ZEB) are buildings with a minimized energy consumption and renewable energy supply with zero greenhouse gas emissions. There is no common accepted definition of zero emission buildings. This is due to issues in defining the boundary of a balance in terms of building site and time frame of this balance. Further, there is no standard on accounting for emissions (on material, components, system, and building level) nor is there a standard for emissions from other building related environments. In this paper the goals for ZEB are specified and implications for components are discussed.
Vacuum insulation panels (VIPs) are regarded as one of the most promising existing high performance thermal insulation solutions on the market today as their thermal performance typically range 5–10 times better than traditional insulation materials. However, the VIPs have several disadvantages such as risk of puncturing by penetration of nails and that they cannot be cut or fitted at the construction site. Furthermore, thermal bridging due to the panel envelope and load-bearing elements may have a large effect on the overall thermal performance. Finally, degradation of thermal performance due to moisture and air diffusion through the panel envelope is also a crucial issue for VIPs. In this work, laboratory investigations have been carried out by hot box measurements. These experimental results have been compared with numerical simulations of several wall structure arrangements of vacuum insulation panels. Various VIP edge and overlap effects have been studied. Measured U-values from hot box VIP large-scale experiments correspond well with numerical calculated U-values when actual values of the various parameters are used as input values in the numerical simulations.
Aerogels are regarded as one of the most promising high performance thermal insulation materials for building applications today. With a thermal conductivity down to 13 mW/(m K) for commercial products they show remarkable characteristics compared to traditional thermal insulation materials. Also the possibility of high transmittances in the solar spectrum is of high interest for the construction sector. With the proper knowledge they give both the architect and engineer the opportunity of re-inventing architectural solutions. Within this work, a review is given on the knowledge of aerogel insulation in general and for building applications in particular.